Capacitor element and semiconductor device

ABSTRACT

A semiconductor device includes a capacitor element including a first comb-shaped interconnection formed over a substrate and including a first comb tooth, a second comb-shaped interconnection formed over the substrate and including a second comb tooth opposed to the first comb tooth, and a first electrode and a second electrode opposed to each other with opposed surfaces of the first electrode and the second electrode intersecting a longitudinal direction of the first comb tooth and the second comb tooth, a first dielectric layer formed between the first electrode and the second electrode, the first electrode being connected to the first comb tooth, and the second electrode being connected to the second comb tooth.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of PCT application No. PCT/JP2007/069375, which was filed on Oct. 3, 2007, and which designated the United States of America, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein are related to a capacitor element and a semiconductor device including the capacitor element.

BACKGROUND

Capacitor elements are important constituent elements in electronic devices, such as low-pass filters, RF (Radio-Frequency) circuits, AD converters, etc.

Recently, as a capacitor element having good voltage characteristics and high frequency characteristics, the MIM (Metal-Insulator-Metal) capacitor element is noted.

Related references are as follows:

Japanese Laid-open Patent Publication No. 2002-124575,

Japanese Laid-open Patent Publication No. 2003-529941,

Japanese Laid-open Patent Publication No. 2003-530699,

Japanese Laid-open Patent Publication No. 2003-536271,

Japanese Laid-open Patent Publication No. 2005-108874,

Japanese Laid-open Patent Publication No. 2006-128164, and

Jonghae Kim et al., “3-Dimensional Vertical Parallel Plate capacitors in an SOI CMOS Technology for Integrated RF Circuits”, 2003 Symposium on VLSI Circuits Digests of Technical Papers, pp. 29-32, June 2003.

SUMMARY

According to one aspect of the embodiment, a capacitor element comprising: a first comb-shaped interconnection formed over a substrate and including a first comb tooth; a second comb-shaped interconnection formed over the substrate and including a second comb tooth opposed to the first comb tooth; a first electrode and a second electrode opposed to each other with opposed surfaces of the first electrode and the second electrode intersecting a longitudinal direction of the first comb tooth and the second comb tooth; and a first dielectric layer formed between the first electrode and the second electrode, the first electrode being connected to the first comb tooth, and the second electrode being connected to the second comb tooth.

According to another aspect of the embodiment, a semiconductor device comprising a capacitor element formed over a semiconductor substrate, the capacitor element including a first comb-shaped interconnection formed over the substrate and including a first comb tooth; a second comb-shaped interconnection formed over the substrate and including a second comb tooth opposed to the first comb tooth; a first electrode and a second electrode opposed to each other with opposed surfaces of the first electrode and the second electrode intersecting a longitudinal direction of the first comb tooth and the second comb tooth; and a first dielectric layer formed between the first electrode and the second electrode, the first electrode being connected to the first comb tooth, and the second electrode being connected to the second comb tooth.

The object and advantages of the embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the embodiments, as claimed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a semiconductor device according to a first embodiment;

FIG. 2 is a sectional view of the semiconductor device according to the first embodiment;

FIG. 3 is a plan view of the semiconductor device according to the first embodiment;

FIGS. 4A to 11 are views of the semiconductor device according to the first embodiment in the steps of the method of manufacturing the semiconductor device, which illustrate the method;

FIGS. 12A to 15 are sectional views of the semiconductor device according to a modification of the first embodiment in the steps of the method of manufacturing the semiconductor device, which illustrate the method;

FIG. 16 is a sectional view of the semiconductor device according to a modification of the first embodiment;

FIG. 17 is a perspective view of a semiconductor device according to a second embodiment;

FIG. 18 is a sectional view of the semiconductor device according to the second embodiment;

FIG. 19 is a plan view of the semiconductor device according to the second embodiment;

FIGS. 20A to 31 are views of the semiconductor device according to the second embodiment in the steps of the method of manufacturing the semiconductor device, which illustrate the method;

FIG. 32 is a sectional view of a semiconductor device according to a modification of the second embodiment;

FIG. 33 is a perspective view of the semiconductor device according to a third embodiment;

FIG. 34 is a sectional view of the semiconductor device according to the third embodiment;

FIG. 35 is a plan view of the semiconductor device according to the third embodiment;

FIGS. 36A to 43 are views of the semiconductor device according to the third embodiment in the steps of the method of manufacturing the semiconductor device, which illustrate the method; and

FIG. 44 is a sectional view of a semiconductor device according to a modification of the third embodiment.

DESCRIPTION OF EMBODIMENTS

The dielectric capacities per a unit area of the proposed capacitor elements are not always sufficiently large. Especially, the low-pass filters, etc. requires extremely large dielectric capacities, and to this end, techniques for improving the dielectric capacitance per a unit area have been expected.

Preferred embodiments of the present invention will be explained with reference to accompanying drawings.

[a] First Embodiment

The capacitor element according to a first embodiment, the semiconductor device including the capacitor element, and their manufacturing method will be explained with reference to FIGS. 1 to 11.

(Capacitor Element and Semiconductor Device)

First, the capacitor element according to the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIGS. 1 to 3. FIG. 1 is a perspective view of the semiconductor device according to the present embodiment, which illustrates the semiconductor device. Inter-layer insulation films 18, 26, 32, 34 burying first electrodes 16 a and second electrodes 16 b are not illustrated. FIG. 2 is a sectional view of the semiconductor device according to the present embodiment. FIG. 3 is a plan view of the semiconductor device according to the present embodiment. FIG. 2 is the sectional view along the A-A′ line in FIG. 3.

As illustrated in FIG. 1, an inter-layer insulation film 12 of, e.g., silicon oxide film is formed on a semiconductor substrate 10 of, e.g., a silicon substrate. On the semiconductor substrate 10, transistors, conductor plugs, interconnections, etc. not illustrated are suitably formed.

On the inter-layer insulation film 12, a first comb-shaped (comb teeth-shaped) interconnection 14 a and a second bomb-shaped (comb teeth-shaped) interconnections 14 b are formed. The first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed on the same layer. The first comb-shaped interconnection 14 a has a plurality of comb teeth 15 a. The plural comb teeth 15 a of the first comb-shaped interconnection 14 a are formed in parallel with each other. The second comb-shaped interconnection 14 b has a plurality of comb teeth 15 b. The plural comb teeth 15 b of the second comb-shaped interconnections 14 b are formed in parallel with each other. The plural comb teeth 15 a of the first comb-shaped interconnection 14 a and the plural comb teeth 15 b of the second comb-shaped interconnection 14 b are arranged alternately therebetween. In other words, the plural comb teeth 15 a of the first comb-shaped interconnection 14 a and the plural teeth 15 b of the second comb-shaped interconnection 14 b are formed in combination with each other. The plural comb teeth 15 a of the first comb-shaped interconnection 14 a and the plural comb teeth 15 b of the second comb-shaped interconnection 14 b are arranged opposed to each other. One of the comb tooth 15 b of the second comb-shaped interconnection 14 b is disposed between one of the comb tooth 15 a of the first comb-shaped interconnection 14 a and the other of the comb tooth 15 b of the first comb-shaped interconnection 14 a. The other of the comb tooth 15 a of the first comb-shaped interconnection 14 a is disposed between one of the comb tooth 15 b of the second comb-shaped interconnection 14 b and the other of the comb tooth 15 b of the second comb-shaped interconnection 14 b. The first comb-shaped interconnection 14 a is connected to, e.g., a first potential. The second comb-shaped interconnection 14 b is connected to, e.g., a second potential which is different from the first potential. The first potential is, e.g., power supply potential. The second potential is, e.g., the ground potential. The gap between the comb teeth 15 a of the first comb-shaped interconnection 14 a and the comb teeth 15 b of the second comb-shaped interconnection 14 b is made small, which makes the gaps between the first electrodes 16 a and the second electrodes 16 b can be made small, whereby the improvement of the dielectric capacitance per a unit area of the capacitor element can be realized.

On the semiconductor substrate 10 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, a plurality of the first electrodes 16 a and a plurality of the second electrodes 16 b are formed, projected perpendicularly to the surface of the semiconductor substrate 10. The plural first electrodes 16 a and the plural second electrodes 16 b are formed alternately and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole (see FIG. 3).

The plural first electrodes 16 a form one electrode of the capacitor element (capacitor unit), and the plural second electrodes 16 b form the other electrode opposed to said one electrode of the capacitor element (capacitor unit).

As will be detailed below, the first electrodes 16 a each comprise a conductor plug 22 a, a linear conduction layer 24 a, conductor plugs 30 a, 30 b, a linear conduction layer 32 a, conductor plugs 38 a, 38 b and a linear conduction layer 40 a sequentially stacked. The first electrodes 16 a are connected to the first comb-shaped interconnection 14 a. More specifically, the first electrodes 16 a are connected to the comb teeth 15 a of the first comb-shaped interconnection 14 a.

As will be detailed below, the second electrodes 16 b each comprise a conductor plug 22 b, a linear conduction layer 24 b, conductor plugs 30 c, 30 d, a linear conduction layer 32 b, conductor plugs 38 a, 38 d and a linear conduction layer 40 b sequentially stacked. The second electrodes 16 b are connected to the second comb-shaped interconnection 14 b. More specifically, the second electrodes 16 b are connected to the comb teeth 15 b of the second comb-shaped interconnection 14 b.

The opposed surfaces of the first electrodes 16 a and the second electrodes 16 b cross the longitudinal direction of the comb teeth of the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b, more specifically, are perpendicular to the longitudinal direction of the comb teeth of the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b.

The plural first electrodes 16 a and the plural second electrodes 16 b are buried in the inter-layer insulation films 18, 26, 34, 42.

On the inter-layer insulation film 12 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, the inter-layer insulation film 18 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 18, contact holes 20 a arriving at the comb tooth 15 a of the first comb-shaped interconnection 14 a and contact holes 20 b arriving at the comb tooth 15 b of the second comb-shaped interconnection 14 b are formed.

In the contact holes 20 a, 20 b, conductor plugs 22 a, 22 b are respectively buried.

On the inter-layer insulation film 18 with the conductor plugs 22 a, 22 b buried in, the linear conduction layers 24 a, 24 b are formed. The linear conduction layer 24 a is connected to the conductor plugs 22 a, and the linear conduction layer 24 b is connected to the conductor plugs 22 b.

On the inter-layer insulation film 18 with the linear conduction layers 24 a, 24 b formed on, the inter-layer insulation film 26 of, e.g., silicon oxide film is formed.

In the inter-layer insulation 26, contact holes 28 a, 28 b respectively arriving at the linear conduction layer 24 a, and contact holes 28 c, 28 d respectively arriving at the linear conduction layer 24 b are formed.

In the contact holes 28 a, 28 b, conductor plugs 30 a, 30 b are respectively buried. The conductor plugs 30 a are connected to one ends of the linear conduction layers 24 a, and the conductor plugs 30 b are connected to the other ends of the linear conduction layers 24 a.

In the contact holes 28 c, 28 d, conductor plugs 30 c, 30 d are respectively buried. The conductor plugs 30 c are connected to one ends of the conduction layers 24 b, and the conductor plugs 30 d are connected to the other ends of the linear conduction layers 24 b.

On the inter-layer insulation film 26 with the conductor plugs 30 a-30 d buried in, linear conduction layers 32 a, 32 b are formed.

The linear conduction layers 32 a have one ends connected to one ends of the linear conduction layers 24 a via the conductor plugs 30 a. The linear conduction layers 32 a have the other ends connected to the other ends of the linear conduction layers 24 a via the conductor plugs 30 b.

The linear conduction layers 32 b have one ends connected to one ends of the linear conduction layers 24 b via the conductor plugs 30 c. The linear conduction layers 32 b have the other ends connected to the other ends of the linear conduction layer 24 b via the conductor plugs 30 d.

On the inter-layer insulation film 26 with the linear conduction layers 32 a, 32 b formed on, the inter-layer insulation film 34 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 34, contact holes 36 a, 36 b respectively arriving at the linear conduction layers 32 a, and contact holes 36 c, 36 d respectively arriving at the linear conduction layers 32 b are formed.

In the contact holes 36 a, 36 b, conductor plugs 38 a, 38 b are respectively buried. The conductor plugs 38 a are connected to one ends of the linear conduction layers 32 a, and the conductor plugs 38 b are connected to the other ends of the linear conduction layers 32 a.

In the contact holes 36 c, 36 d, conductor plugs 38 c, 38 d are respectively buried. The conductor plugs 38 c are connected to one ends of the linear conduction layers 32 b, and the conductor plugs 38 d are connected to the other ends of the linear conduction layers 32 b.

On the inter-layer insulation film 34 with the conductor plugs 38 a-38 d buried in, linear conduction layers 40 a, 40 b are formed.

The linear conduction layers 40 a have one ends connected to one ends of the linear conduction layers 32 a via the conductor plugs 38 a. The linear conduction layers 40 a have the other ends connected to the other ends of the linear conduction layers 32 a via the conductor plugs 38 b.

The linear conduction layers 40 b have one ends connected to one ends of the linear conduction layers 32 b via the conductor plugs 38 c. The linear conduction layers 40 b have the other ends connected to the other ends of the linear conduction layers 32 b via the conductor plugs 38 d.

On the inter-layer insulation film 34 with the linear conduction layers 40 a, 40 b formed on, the inter-layer insulation film 42 of, e.g., silicon oxide film is formed.

Thus, the first electrodes 16 a each including the conductor plug 22 a, the conduction layer 24 a, the conductor plugs 30 a, 30 b, the conduction layer 32 a, the conductor plugs 38 a, 38 b and the conduction layer 40 a are constituted.

The second electrodes 16 b each including the conductor plug 22 b, the conduction layer 24 b, the conductor plugs 30 c, 30 d, the conduction layer 32 b, the conductor plugs 38 c, 38 d and the conduction layer 40 b are constituted.

As described above, the first electrodes 16 a and the second electrodes 16 b are alternately laid out and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole.

The inter-layer insulation films 18, 26, 34, 42 present between the first electrodes 16 a and the second electrodes 16 b function as the dielectric layers of the capacitor element.

The first electrodes 16 a, the dielectric layers 18, 26, 34, 42 and the second electrodes 16 b form the capacitor element.

Thus, the semiconductor device according to the present embodiment is constituted.

According to the present embodiment, the first electrodes 16 a and the second electrodes 16 b are connected respectively to the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b which are formed in the same layer. This opposes the n-th layer conductor plugs forming a part of the first electrodes 16 a and the n-th conductor plugs forming a part of the second electrodes 16 b to each other. This opposes the m-th conduction layer 40 a forming a part of the first electrodes 16 a and the m-th conduction layer 40 b forming a part of the second electrodes 16 b to each other. According to the present embodiment, the dielectric capacitance between the first electrodes 16 a and the second electrodes 16 b can be ensured large. Thus, according to the present embodiment, the dielectric capacitance per a unit area can be made sufficiently large.

According to the present embodiment, the first electrodes 16 a and the second electrodes 16 b are alternately formed and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole. Thus, according to the present embodiment, not only the parallel-plate capacitance between the first electrodes 16 a and the second electrodes 16 b but also the fringe capacitance between the first electrodes 16 a and the second electrodes 16 b can be ensured large. Thus, according to the present embodiment, the dielectric capacitance per a unit area can be made sufficiently large.

According to the present embodiment, the first electrodes 16 a and the second electrodes 16 a are formed, projected perpendicularly to the semiconductor substrate 10. Thus, the gap between the first electrodes 16 a and the second electrodes 16 b can be made sufficiently smaller in comparison with the gap provided by forming the first electrodes 16 a and the second electrodes 16 b on different inter-layer insulation films in parallel with the surfaces of the inter-layer insulation films. Thus, according to the present embodiment, the capacitor can have a large the dielectric capacitance per a unit area.

(Manufacturing Method of Capacitor Element and Semiconductor Device)

Next, the method of manufacturing the capacitor element according to the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIGS. 4A to 11. FIGS. 4A to 11 are views of the semiconductor device according to the present embodiment in the steps of the semiconductor manufacturing method, which illustrate the method. FIG. 4A, FIG. 5A, FIG. 6A, FIG. 7A, FIG. 8A and FIG. 9A are sectional views and correspond respectively to the A-A′ line section of FIG. 4B, FIG. 5B, FIG. 6B, FIG. 7B, FIG. 8B and FIG. 9B. FIG. 10 is a sectional view, and FIG. 11 is a plan view. FIG. 10 corresponds to the A-A′ line section of FIG. 11.

First, as illustrated in FIGS. 4A and 4B, the inter-layer insulation film 12 of, e.g., silicon oxide film is formed on the semiconductor substrate 10 of, e.g., a silicon substrate.

Next, on the entire surface, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed by, e.g., sputtering.

Then, the conduction film is patterned by photolithography. Thus, as illustrated in FIG. 4B, on the inter-layer insulation film 12, a first comb-shaped interconnection 14 a having a plurality of comb teeth 15 a and a second comb-shaped interconnection 14 b having a plurality of comb teeth 15 b are formed.

The case that the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. The method for forming the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b is not limited to this. The first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b may be formed by damascene.

FIGS. 12A to 15 are sectional views of the semiconductor device according to the present embodiment in the steps of the semiconductor manufacturing method according to a modification, which illustrate the method.

First, as illustrated in FIG. 12A, trenches 66 are formed in the inter-layer insulation film 13 formed on the inter-layer insulation film 12.

Then, on the entire surface, a barrier metal 68 of TiN or others is formed by, e.g., sputtering.

Next, on the entire surface, a seed layer (not illustrated) of Cu is formed by, e.g., sputtering.

Then, on the entire surface, a conduction film 70 of Cu is formed by electroplating (see FIG. 12B).

Then, by CMP (Chemical Mechanical Polishing), the conduction film 70, the seed layer and the barrier metal 68 are polished until the surface of the inter-layer insulation film 13 is exposed. Thus, the first comb-shaped interconnection 14 a of Cu and the second comb-shaped interconnection 14 b of Cu are buried in the inter-layer insulation film 13 (see FIG. 13A).

Thus, the first comb-shaped interconnection 15 a and the second comb-shaped interconnection 15 b may be formed by damascene.

Next, as illustrated in FIGS. 5A and 5B, on the inter-layer insulation film 12 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, the inter-layer insulation film 18 of, e.g., silicon oxide film is formed.

Next, by, e.g., photolithography, the contact holes 20 a arriving at the comb-teeth 15 a of the first comb-shaped interconnection 14 a and the contact holes 20 b arriving at the comb-teeth 15 b of the second comb-shaped interconnection 14 b are formed in the inter-layer insulation film 18.

Next, on the entire surface, a barrier film and a tungsten film are formed by, e.g., CVD. The material of the barrier film can be Ti, TiN, Ta, TaN or others.

Then, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 18 is exposed. Thus, the conductor plugs 22 a, 22 b of, e.g., tungsten are respectively buried in the contact holes 20 a, 20 b.

Next, on the entire surface, a conduction film of aluminum or others of a 200-300 nm-film thickness is formed by, e.g., sputtering.

Then, the conduction film is patterned by photolithography. Thus, the linear conduction layers 24 a and the linear conduction layers 24 b are formed on the inter-layer insulation film 18. These conduction layers 24 a, 24 b are alternately formed and, as viewed from above the semiconductor substrate 10, the conduction layers 24 a, 24 b are arranged in a matrix as a whole. One ends of the linear conduction layers 24 a are connected to the conductor plugs 22 a. The conduction layers 24 a are electrically connected to the comb-shaped interconnections 14 a via the conductor plugs 22 a. One ends of the linear conduction layers 24 b are connected to the conductor plugs 22 b. The conduction layers 24 b are electrically connected to the comb-shaped interconnection 14 b via the conductor plugs 22 b (see FIGS. 6A and 6B).

The case that the conduction layers 24 a and the conduction layers 24 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method forming the conduction layers 24 a and the conduction layer 24 b is not limited to this. The conduction layers 24 a and the conduction layers 24 b may be formed by dual damascene as follows.

First, as illustrated in FIG. 13B, the contact holes 20 a arriving at the first comb-shaped interconnection 15 a and the contact holes 20 b arriving at the second comb-shaped interconnection 15 b are formed in the inter-layer insulation film 18.

Next, as illustrated in FIG. 14A, trenches 72 a, 72 b for the conduction layers 24 a, 24 b to be buried in are formed in the inter-layer insulation film 18.

Then, on the entire surface, the barrier metal 74 of TiN or others is formed by, e.g., sputtering.

Next, on the entire surface, the seed layer (not illustrated) of Cu is formed by, e.g., sputtering.

Then, on the entire surface, the conduction film 76 of Cu is formed by electroplating (see FIG. 14B).

Next, the conduction film 76, the seed layer and the barrier metal 74 are polished by CMP until the surface of the inter-layer insulation film 18 is exposed. Thus, the conductor plugs 22 a of Cu and the conduction layer 24 a of Cu are formed integral, and the conductor plugs 22 b of Cu and the conduction layer 24 b of Cu are formed integral.

As described above, the conductor plugs 22 a, 22 b and the conduction layers 24 a, 24 b may be formed dual damascene.

Next, as illustrated in FIGS. 7A and 7B, on the inter-layer insulation film 18 with the conduction layers 24 a, 24 b formed on, the inter-layer insulation film 26 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Next, by photolithography, the contact holes 28 a arriving at one ends of the conduction layers 24 a and the contact holes 28 b arriving at the other ends of the conduction layers 24 a, and the contact holes 28 c arriving at one ends of the conduction layers 24 b and the contact holes 28 d arriving at the other ends of the conduction layers 24 b are formed in the inter-layer insulation film 26.

Then, a barrier film and a tungsten film are formed on the entire surface by, e.g., CVD.

Next, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 26 is exposed. Thus, the conductor plugs 30 a-30 d of, e.g., tungsten are buried respectively in the contact holes 28 a-28 d.

Next, on the entire surface, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed by, e.g., sputtering.

Then, the conduction film is patterned by photolithography. Thus, the linear conduction layers 32 a and the linear conduction layers 32 b are formed on the inter-layer insulation film 26. These conduction layers 32 a, 32 b are formed alternately and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole (see FIGS. 8A and 8B). One ends of the linear conduction layers 32 a are connected to the conductor plugs 30 a, and the other ends of the linear conduction layers 32 a are connected to the conductor plugs 30 b. The conduction layers 32 a are electrically connected to the conduction layers 24 a, 24 b via the conductor plugs 30 a, 30 b. In the present embodiment, the conduction layers 32 a are each connected to the conduction layers 24 a by two conductor plugs 30 a, 30 b, which can ensure the reliability of the connection between the conduction layers 32 a and the conduction layer 24 a. The conduction layers 32 b are electrically connected to the conduction layers 24 b via the conductor plugs 30 c, 30 d. In the present embodiment, the conduction layers 32 b are each electrically connected to the conduction layers 24 a by two conductor plugs 30 c, 30 d, which can ensure the connection between the conduction layers 32 b and the conduction layers 24 b. In the present embodiment, the opposed area of the conductor plugs 30 a, 30 b and the conductor plugs 30 c, 30 d can be made larger in comparison with the opposed area provided by connecting the conduction layers 32 a and the conduction layers 24 a by one conductor plugs 30 a and connecting the conduction layers 32 b and the conduction layers 24 b by one conductor plugs 30 c. Thus, according to the present embodiment, the dielectric capacitance per a unit area can be improved.

The case that the conduction layers 32 a and the conduction layers 32 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method of forming the conduction layers 32 a, the conduction layers 32 b is not limited to this. For example, it is possible that contact holes for the conductor plugs 30 a-30 d to be buried in and trenches for the conduction layers 32 a, 32 b to be buried in are formed, a conduction film of Cu is formed in the contact holes and trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conductor plugs 30 a-30 d of Cu and the conduction layers 32 a, 32 b of Cu in the inter-layer insulation film (not illustrated). That is, the conductor plugs 30 a-30 d and the conduction layers 32 a, 32 b may be formed by dual damascene. In this case, the conductor plugs 30 a, 30 b of Cu and the conduction layers 32 a are formed integral, and the conductor plugs 30 c, 30 d of Cu and the conduction layer 32 b are formed integral.

Next, all over the inter-layer insulation film 26 with the conduction layers 32 a, 32 b formed on, the inter-layer insulation film 34 of, e.g., silicon oxide film is formed by, e.g., CVD.

Next, the contact holes 38 a arriving at one ends of the conduction layers 32 a, the contact holes 38 b arriving at the other ends of the conduction layers 32 a, the contact holes 38 c arriving at one ends of the conduction layers 32 b and the contact holes 38 d arriving at the other ends of the conduction layers 32 b are formed in the inter-layer insulation film 34 by photolithography.

Next, a barrier film and a tungsten film are formed on the entire surface by, e.g., CVD.

Then, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 34 is exposed. Thus, the conductor plugs 38 a-38 d of, e.g., tungsten are buried respectively in the contact holes 36 a-36 d (see FIGS. 9A and 9B).

Next, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed on the entire surface by, e.g., sputtering.

Next, the conduction film is patterned by photolithography. Thus, on the inter-layer insulation film 34, the linear conduction layers 40 a of the conduction film and the linear conduction layers 40 b of the conduction film are formed. These conduction layers 40 a, 40 b are formed alternately and, as viewed form above the semiconductor substrate 10, are arranged in a matrix as a whole. One ends of the linear conduction layers 40 a are connected to the conductor plugs 38 a, and the other ends of the linear conduction layers 40 a are connected to the conductor plugs 38 b. One ends of the linear conduction layers 40 b are connected to the conductor plugs 38 c, and the other ends of the linear conduction layers 40 b are connected to the conductor plugs 38 d.

The case that the conduction layers 40 a and the conduction layers 40 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method of forming the conduction layers 40 a and the conduction layers 40 b is not limited to this. For example, it is possible that the contact holes for the conductor plugs 38 a-38 d to be buried in and the trenches for the conduction layers 40 a, 40 b to be buried in are formed, a conduction film of Cu is formed in the contact holes and the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conductor plugs 38 a-38 d of Cu and the conduction layers 40 a, 40 b of Cu are buried in the inter-layer insulation film (not illustrated). That is, the conductor plugs 38 a-38 d and the conduction layers 32 a, 32 b may be formed by dual damascene. In this case, the conductor plugs 38 a, 38 b of Cu and the conduction layers 40 a of Cu are formed integral, and the conductor plugs 38 c, 38 d of Cu and the conduction layers 40 b of Cu are formed integral.

Next, the inter-layer insulation film 42 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Thus, the semiconductor device according to the present embodiment is manufactured (see FIGS. 10 and 11).

According to the present embodiment, the conductor plugs 22 a, the conduction layers 24 a, the conductor plugs 30 a, 30 b, the conduction layers 32 a, the conductor plugs 38 a, 38 b and the conduction layers 40 a are suitably stacked to thereby form the first electrodes 16 a, and the conductor plugs 22 b, the conduction layers 24 b, the conductor plugs 30 c, 30 d, the conduction layers 32 b, conductor plugs 38 c, 38 d and the conduction layers 40 b are suitably stacked to thereby form the second electrodes 16 b. Thus, according to the present embodiment, no special manufacturing process, special interconnection rules, etc. are necessary. Thus, according to the present embodiment, the capacitor element and the semiconductor device including the capacitor element can be manufactured by the usual manufacturing process.

(Modification)

Next, The capacitor element according to one example of modifications of the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIG. 16. FIG. 16 is a sectional view of the semiconductor device according to the present modification.

The capacitor element according to the present embodiment and the semiconductor device including the capacitor element is characterized mainly in that the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b are respectively connected by linear conduction layers 30 e, 30 f buried in the inter-layer insulation film 26, and the linear conduction layers 32 a, 32 b and the linear conduction layers 40 a, 40 b are respectively connected by linear conduction layers 38 e, 38 f buried in the inter-layer insulation film 34.

As described above, the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b may be respectively connected by the linear conduction layers 30 e, 30 f without being respectively connected by the conductor plugs 30 a-30 d. The linear conduction layers 32 a, 32 b and the linear conduction layers 40 a, 40 b may be respectively connected by the linear conduction layers 38 e, 38 f without being respectively connected by the conductor plugs 38 a-38 d.

[b] Second Embodiment

The capacitor element according to a second embodiment and the semiconductor device including the capacitor element, and their manufacturing method will be explained with reference to FIGS. 17 to 31. The same members of the capacitor element and the semiconductor device, etc. according to the first embodiment illustrated in FIGS. 1 to 16 are represented by the same reference numbers not to repeat or to simplify their explanation.

(Capacitor Element and Semiconductor Device)

First, the capacitor element according to the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIGS. 17 to 19. FIG. 17 is a perspective view of the semiconductor device according to the present embodiment. In FIG. 17, the inter-layer insulation films 18, 26, 34 with the first electrodes 16 a and the second electrodes 16 b buried in, and the inter-layer insulation films 46, with the third electrodes 16 c and the fourth electrodes 16 d buried in are omitted. FIG. 18 is a sectional view of the semiconductor device according to the present embodiment. FIG. 19 is a plan view of the semiconductor device according to the present embodiment. FIG. 18 is the section along the A-A′ line in FIG. 19.

The semiconductor device according to the present embodiment is characterized mainly in that below the layer with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, third electrodes 16 c electrically connected to the first comb-shaped interconnection 14 a and fourth electrodes 16 d electrically connected to the second comb-shaped interconnection 14 b are formed.

As illustrated in FIG. 18, on the semiconductor substrate 10 of, e.g., a silicon substrate, the inter-layer insulation film 12 of, e.g., silicon oxide film is formed.

On the semiconductor substrate 10 with the inter-layer insulation film 12 formed on, a plurality of third electrodes 16 c and a plurality of the fourth electrodes 16 d are formed, projected perpendicularly to the surface of the semiconductor substrate 10.

The plural third electrodes 16 c and the plural fourth electrodes 16 d are alternately formed and, as viewed form above the semiconductor substrate 10, are arrange in a matrix as a whole. The plural third electrodes 16 c and the plural fourth electrodes 16 d are buried by the inter-layer insulation films 46, 54.

The inter-layer insulation films 46, 54 between the third electrodes 16 a and the fourth electrodes 16 b function as the dielectric layers of the capacitor element.

As will be detailed below, the third electrodes 16 a are formed of the linear conduction layers 44 a, the conductor plugs 50 a, 50 b, the linear conduction layers 52 a and the conductor plugs 58 a sequentially stacked.

As will be detailed below, the fourth electrodes 16 b are formed of the linear conduction layers 44 b, the conductor plugs 50 c, 50 d, the linear conduction layers 52 b and the conductor plugs 58 b sequentially stacked.

On the inter-layer insulation film 12, the linear conduction layers 44 a, 44 b are formed. The conduction layers 44 a, 44 b are alternately formed and, as viewed from the semiconductor substrate 10, are arranged in a matrix as a whole.

On the inter-layer insulation film 12 with linear conduction layers 44 a, 44 b formed on, the inter-layer insulation film 46 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 46, the contact holes 48 a, 48 b respectively arriving at the linear conduction layers 44 a and the contact holes 48 c, 48 d respectively arriving at the linear conduction layers 44 b are formed.

The conductor plugs 50 a, 50 b are buried respectively in the contact holes 48 a, 48 b. The conductor plugs 50 a are connected to one ends of the linear conduction layers 44 a, and the conductor plugs 50 b are connected to the other ends of the linear conduction layers 44 a.

In the contact holes 48 c, 48 d, the conductor plugs 50 c, 50 d are respectively buried. The conductor plugs 50 c are connected to one ends of the linear conduction layers 44 b, and the conductor plugs 50 d are connected to the other ends of the linear conduction layer 44 b.

On the inter-layer insulation film 46 with the conductor plugs 50 a-50 d buried in, the linear conduction layers 52 a, 52 b are formed.

On the inter-layer insulation film 46 with the linear conduction layers 52 a, 52 b formed on, the inter-layer insulation film 54 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 54, the contact holes 56 a arriving at one ends of the linear conduction layers 52 a and the contact holes 56 b arriving at one ends of the linear conduction layers 52 b are formed.

In the contact holes 56 a, 56 b, the conductor plugs 58 a, 58 b are respectively buried. The conductor plugs 58 a are connected to one ends of the conduction layers 52 a, and the conductor plugs 58 b are connected to one ends of the linear conduction layers 52 b.

On the inter-layer insulation film 54 with the conductor plugs 58 a, 58 b buried in, the first linear comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed (see FIG. 19). The first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed on the same layer. The plural comb teeth 15 a of the first comb-shaped interconnection 14 a and the plural comb teeth 15 b of the second comb-shaped interconnection 14 b are formed alternately. The tops of the third electrodes 16 c are connected to the first comb-shaped interconnection 14 a. More specifically, the tops of the third electrodes 16 c are connected to the comb teeth 15 a of the first comb-shaped interconnection 14 a. The tops of the fourth electrodes 16 d are connected to the second comb-shaped interconnection 14 b. More specifically, the tops of the fourth electrodes 16 d are connected to the comb teeth 15 b of the second comb-shaped interconnection 14 b. The first comb-shaped interconnection 14 a is connected to, e.g., a first potential. The second comb-shaped interconnection 14 b is connected to, e.g., a second potential different from the first potential. The first potential is, e.g., a power supply potential. The second potential is, e.g., the ground potential.

On the inter-layer insulation film 54 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, the plural first electrodes 16 a and the plural second electrodes 16 b are formed, projected perpendicularly to the surface of the semiconductor substrate 10. The plural first electrodes 16 a and the plural second electrodes 16 b are alternately formed and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole.

As will be detailed below, the first electrodes 16 a are formed of the conductor plugs 22 a, the linear conduction layers 24 a, the conductor plugs 30 a, 30 b and the linear conduction layer 32 a sequentially stacked.

As will be detailed below, the second electrodes 16 b are formed of the conductor plugs 22 b, the linear conduction layers 24 b, the conductor plugs 30 c, 30 d and the linear conduction layer 32 b sequentially stacked.

On the inter-layer insulation film 54 with the first comb-shaped interconnection 14 a and the comb-shaped interconnection 14 b formed on, the inter-layer insulation film 18 of, e.g. silicon oxide film is formed.

In the inter-layer insulation film 18, the contact holes 20 a arriving at the comb teeth 15 a of the first comb-shaped interconnection 14 a and the contact holes 20 b arriving at the comb teeth 15 b of the second comb-shaped interconnection 14 b are formed.

In the contact holes 20 a, 20 b, the conductor plugs 22 a, 22 b are respectively buried.

On the inter-layer insulation film 18 with the conductor plugs 22 a, 22 b buried in, the linear conduction layers 24 a, 24 b are formed. The linear conduction layers 24 a are connected to the conductor plugs 22 a, and the linear conduction layers 24 b are connected to the conductor plugs 22 b.

On the inter-layer insulation film 18 with the linear conduction layers 24 a, 24 b formed on, the inter-layer insulation film 26 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 26, the contact holes 28 a, 28 b respectively arriving at the linear conduction layers 24 a and the contact holes 28 c, 28 d respectively arriving at the linear conduction layers 24 b are formed.

In the contact holes 28 a, 28 b, the conductor plugs 30 a, 30 b are respectively buried. The conductor plugs 30 a are connected to one ends of the linear conduction layers 24 a, and the conductor plugs 30 b are connected to the other ends of the linear conduction layers 24 a.

In the contact holes 28 c, 28 d, the conductor plugs 30 c, 30 d are respectively buried. The conductor plugs 30 c are connected to one ends of the linear conduction layers 24 b, and the conductor plugs 30 d are connected to the other ends of the linear conduction layer 24 b.

On the inter-layer insulation film 26 with the conductor plugs 30 a-30 d buried in, the linear conduction layers 32 a, 32 b are formed.

The linear conduction layers 32 a have one ends connected to one ends of the linear conduction layers 24 a via the conductor plugs 30 a. The linear conduction layers 32 a have the other ends connected to the linear conduction layers 24 a via the conductor plugs 30 b.

The linear conduction layers 32 b have one ends connected to one ends of the linear conduction layers 24 b via the conductor plugs 30 c. The linear conduction layers 32 b have the other ends connected to the other ends of the linear conduction layers 24 b via the conductor plugs 30 d.

On the inter-layer insulation film 26 with the linear conduction layers 32 a, 32 b formed on, the inter-layer insulation film 34 of, e.g., silicon oxide film is formed.

Thus, the capacitor element according to the present embodiment and the semiconductor device including the capacitor element are constituted.

According to the present embodiment, the first electrodes 16 a and the third electrodes 16 c connected to the first potential are formed respectively above and below the first comb-shaped interconnection 14 a, and the second electrodes 16 b and the fourth electrodes 16 d connected to the second potential are formed respectively above and below the second comb-shaped interconnection 14 b. Thus, according to the present embodiment, the electric resistance from the first comb-shaped interconnection 14 a to the terminals of the first electrodes 16 a, the electric resistance from the first comb-shaped interconnection 14 a to the terminals of the third electrodes 16 c, the electric resistance from the second comb-shaped interconnection 14 b to the terminals of the second electrodes 16 b, and the electric resistance from the second comb-shaped interconnection 14 b to the terminals of the fourth electrodes 16 d can be respectively small, whereby resultantly the capacitor element can have good frequency characteristics.

(Manufacturing Method of Capacitor Element and Semiconductor Device)

Next, the method of manufacturing the capacitor element according to the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIGS. 20A to 31. FIGS. 20A to 31 views of the semiconductor device according to the present embodiment in the steps of the method of manufacturing the semiconductor device. FIG. 20A, FIG. 21A, FIG. 22A, FIG. 23A, FIG. 24A and FIG. 25A are sectional views respectively along the A-A′ line in FIG. 20B, FIG. 21B, FIG. 22B, FIG. 23B, FIG. 24B and FIG. 25B. FIG, 26 is a sectional view, and FIG. 27 is a plan view. FIG. 26 is the sectional view along the A-A′ line in FIG. 27. FIG. 28 is a sectional view, and FIG. 29 is a plan view. FIG. 28 is the sectional view along the A-A′ line in FIG. 29. FIG. 30 is a sectional view, and FIG. 31 is a plan view. FIG. 30 is the sectional view along the A-A′ in FIG. 31.

First, on the semiconductor substrate 10 of, e.g., a silicon substrate, the inter-layer insulation film 12 of, e.g., silicon oxide film is formed.

Next, on the entire surface, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed by, e.g., sputtering.

Then, the conduction film is patterned by photolithography. Thus, on the inter-layer insulation film 12, the linear conduction layers 44 a, 44 b are formed. The conduction layers 44 a, 44 b are alternately formed and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole (see FIGS. 20A and 20B).

The case that the conduction layers 44 a, 44 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method forming the conduction layers 44 a, 44 b is not limited to this. It is possible that trenches are formed in the inter-layer insulation film, a conduction film of Cu is formed in the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conduction layers 44 a of Cu and the conduction layers 44 b of Cu in the inter-layer insulation film (not illustrated). That is, the conduction layers 44 a, the conduction layers 44 b may be buried in the inter-layer insulation film by single damascene.

Next, the inter-layer insulation film 46 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Then, in the inter-layer insulation film 46, the contact holes 48 a arriving at one ends of the conduction layers 44 a, the contact holes 48 b arriving at the other ends of the conduction layers 44 a, the contact holes 48 c arriving at one ends of the conduction layers 44 b and the contact holes 48 d arriving at the other ends of the conduction layers 44 b are formed by photolithography (see FIGS. 21A and 21B).

Next, on the entire surface, a conduction film of aluminum or others of an about 200-300 film thickness is formed by, e.g., sputtering.

Then, the conduction film is patterned by photolithography. Thus, on the inter-layer insulation film 46, the linear conduction layers 52 a and the linear conduction layers 52 b are formed. The conduction layers 52 a, 52 b are alternately formed and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole (see FIGS. 22A and 22B). The linear conduction layers 52 a have one ends connected to the conductor plugs 50 a, and have the other ends connected to the conductor plugs 50 b. The conduction layers 52 a are electrically connected to the linear conduction layers 44 a, 44 b via the conductor plugs 50 a, 50 b. The conduction layers 52 b are electrically connected to the conduction layers 44 b via the conductor plugs 50 c, 50 d.

The case that the conduction layers 52 a and the conduction layers 52 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method of forming the conduction layers 52 a and the conduction layers 52 b is not limited to this. For example, it is possible that the contact holes for the conductor plugs 50 a-50 d to be buried in and the trenches for the conduction layers 52 a, 52 b to be buried in are formed in the inter-layer insulation film, a conduction film of Cu is formed in the contact holes and the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conductor plugs 50 a-50 d of Cu and the conduction layers 52 a, 52 b of Cu in the inter-layer insulation film (not illustrated). That is, the conductor plugs 50 a-50 d and the conduction layers 52 a, 52 b may be formed by dual damascene. In this case, the conductor plugs 50 a, 50 b of Cu and the conduction layers 52 a of Cu are formed integral, and the conductor plugs 50 c, 50 d of Cu and the conduction layers 52 b of Cu are formed integral.

Next, on the inter-layer insulation film 46 with the conduction layers 52 a, 52 b formed on, the inter-layer insulation film 54 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Then, by photolithography, the contact holes arriving at one ends of the conduction layers 52 a and the contact holes 56 b arriving at one ends of the conduction layers 52 b are formed in the inter-layer insulation film 54.

Next, on the entire surface, a barrier film and a tungsten film are formed by, e.g., CVD.

Next, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 54 is exposed. Thus, the conductor plugs 58 a, 58 b of, e.g., tungsten are buried in the contact holes 56 a, 56 b, respectively (see FIG. 23A and 23B).

Then, on the entire surface, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed by, e.g., sputtering.

Next, the conduction film is patterned by photolithography. Thus, on the inter-layer insulation film 54, the first comb-shaped interconnection 14 a having the plural comb teeth 15 a and the second comb-shaped interconnection 14 b having the plural comb teeth 15 b are formed (see FIGS. 24A and 24B).

The case that the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method of forming the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b is not limited to this. For example, it is possible that the contact holes for the conductor plugs 58 a, 58 b to be buried in and trenches for the comb-shaped interconnections 14 a, 14 b to be buried in are formed in the inter-layer insulation film, a conduction film of Cu is formed in the contact holes, the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conductor plugs 58 a, 58 b of Cu and the comb-shaped interconnections 14 a, 14 b of Cu in the inter-layer insulation film (not illustrated). That is, the conductor plugs 58 a, 58 b and comb-shaped interconnections 14 a, 14 b may be formed by dual damascene. In this case, the conductor plug 58 a of Cu and the first comb-shaped interconnections 14 a of Cu are formed integral, and the conductor plugs 58 b and the second comb-shaped interconnections 14 b of Cu are formed integral.

Next, on the inter-layer insulation film 54 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed on, the inter-layer insulation film 18 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Next, by, e.g., photolithography, the contact holes 20 a arriving at the first comb-shaped interconnection 14 a and the contact holes 20 b arriving at the second comb-shaped interconnection 14 b are formed in the inter-layer insulation film 18.

Next, a barrier film and a tungsten film are formed on the entire surface by, e.g., CVD.

Then, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 18 is exposed. Thus, the conductor plugs 22 a, 22 b of, e.g., tungsten are buried in the contact holes 20 a, 20 b (see FIGS. 25A and 25B).

Next, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed on the entire surface by, e.g., sputtering.

Next, the conduction film is patterned by photolithography. Thus, the linear conduction layers 24 a and the linear conduction layers 24 b are formed on the inter-layer insulation film 18. The conduction layers 24 a, 24 b are alternately formed and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole. The linear conduction layers 24 a have one ends connected to the conductor plugs 22 a. The conduction layers 24 a are electrically connected to the comb-shaped interconnection 14 a via the conductor plugs 22 a. The linear conduction layers 24 b have one ends connected to the conductor plugs 22 b. The conduction layers 24 b are electrically connected to the comb-shaped interconnection 14 b via the conductor plugs 22 b (see FIG. 26 and FIG. 27).

The case that the conduction layers 24 a and the conduction layers 24 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method of forming the conduction layers 24 a and the conduction layer 24 b is not limited to this. For example, it is possible that contact holes for the conductor plugs 22 a, 22 b to be buried in and trenches for the conduction layers 24 a, 24 b to be buried in are formed in the inter-layer insulation film, a conduction film of Cu is formed in the contact holes and the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the plugs 22 a, 22 b of Cu and the conduction layers 24 a, 24 b of Cu in the inter-layer insulation film (not illustrated). That is, the conductor plugs 22 a, 22 b and the conduction layers 24 a, 24 b may be formed by dual damascene. In this case, the conductor plugs 22 a of Cu and the conduction layer 24 a of Cu are formed integral, and the conductor plugs 22 b of Cu and the conduction layers 24 b of Cu are formed integral.

Then, on the inter-layer insulation film 18 with the conduction layers 24 a, 24 b formed on, the inter-layer insulation film 26 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Next, the contact holes 28 a arriving at one ends of the conduction layers 24 a, the contact holes 28 b arriving at the other ends of the conduction layers 24 a, the contact holes 28 c arriving at one ends of the conduction layers 24 b, and the contact holes 28 d arriving at one ends of the conduction layers 24 b are formed in the inter-layer insulation film 26 by photolithography.

Next, a barrier film and a tungsten film are formed on the entire surface by, e.g., CVD.

Next, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 26 is exposed. Thus, the conductor plugs 30 a-30 d of, e.g., tungsten are buried respectively in the contact holes 28 a-28 d (see FIG. 28 and FIG. 29).

Next, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed on the entire surface by, e.g., sputtering.

Then, the conduction film is patterned by photolithography. Thus, the linear conduction layers 32 a and the linear conduction layers 32 b are formed on the inter-layer insulation film 26. The conduction layers 32 a, 32 b are alternately formed and, as viewed from above the semiconductor substrate 10, are arranged in a matrix as a whole. The linear conduction layers 32 a have one ends connected to the conductor plugs 30 a and the other ends connected to the conductor plugs 30 b. The conduction layers 32 a are electrically connected to the conduction layers 24 a, 234 b via the conductor plugs 30 a, 30 b. The conduction layer 32 b is electrically connected to the conduction layer 24 b via the conductor plugs 30 c, 30 d.

The case that the conduction layers 32 a and the conduction layer 32 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified here. However, the method of forming the conduction layers 32 a and the conduction layers 32 b is not limited to this. For example, it is possible that contact holes for the conductor plugs 30 a-30 d to be buried in and trenches for the conduction layers 32 a, 32 b to be buried in are formed in the inter-layer insulation film, a conduction film of Cu is formed in the contact holes and the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conductor plugs 30 a-30 d of Cu and the conduction layers 32 a, 32 b in the inter-layer insulation film (not illustrated). That is, the conductor plugs 30 a-30 d and the conduction layers 32 a, 32 b may be formed by dual damascene. In this case, the conductor plugs 30 a, 30 b of Cu and the conduction layers 32 a of Cu are formed integral, and the conductor plugs 30 c, 30 d of Cu and the conduction layers 32 b of Cu are formed integral

Next, on the entire surface, the inter-layer insulation film 34 of, e.g., silicon oxide film is formed by, e.g., CVD (see FIG. 30 and FIG. 31).

Thus, the semiconductor device according to the present embodiment is manufactured.

(Modification)

Next, the capacitor element according to a modification of the present embodiment and the semiconductor device including the capacitor will be explained with reference to FIG. 32. FIG. 32 is a sectional view of the semiconductor device according to the present modification.

The capacitor element according to the present modification and the semiconductor device including the capacitor element is characterized mainly in that the linear conduction layers 44 a, 44 b and the linear conduction layers 52 a, 52 b are respectively connected by the linear conduction layers 48 e, 48 f buried in the inter-layer insulation film 46, and the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b are connected by the linear conduction layers 30 e, 30 f buried in the inter-layer insulation film 26.

As described above, the linear conduction layers 44 a, 44 b and the linear conduction layers 52 a, 52 b may be connected respectively by the linear conduction layers 48 e, 48 f without connecting the linear conduction layers 44 a, 44 b and the linear conduction layers 52 a, 52 b respectively by the conductor plugs 50 a-50 d. The linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b may be connected respectively by the linear conduction layers 30 e, 30 f without connecting the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b respectively by the conductor plugs 30 a-30 d.

[c] Third Embodiment

The capacitor element according to a third embodiment and the semiconductor device including the capacitor element, and their manufacturing method will be explained with reference to FIGS. 33 to 43. The same members of the capacitor element according to the present embodiment and the semiconductor device including the capacitor element, etc. as those of the capacitor element and the semiconductor device, etc. according to the first or the second embodiment illustrated in FIGS. 1 to 28 are represented by the same reference numbers not to repeat or to simplify their explanation.

(Capacitor Element and Semiconductor Device)

First, the capacitor element according to the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIGS. 33 to 35. FIG. 33 is a perspective view of the semiconductor device according to the present embodiment. In FIG. 33, the inter-layer insulation films 18, 26, 34, 42 formed burying the first electrodes 16 a and the second electrodes 16 b are omitted. FIG. 34 is a sectional view of the semiconductor device according to the present embodiment. FIG. 35 is a plan view of the semiconductor device according to the present embodiment. FIG. 34 is the sectional view along hte A-A′ line in FIG. 35.

The semiconductor device according to the present embodiment is characterized mainly in that a first comb-shaped interconnection 14 a is formed below the first electrodes 16 a, also above the first electrodes 16 a, a third comb-shaped interconnection 64 a electrically connected to the first electrodes 16 a is formed, a second comb-shaped interconnection 14 b is formed below the second electrodes 16 b, and also above the second electrodes 16 b, a fourth comb-shaped interconnection 64 b electrically connected to the second electrodes 16 b is formed.

As illustrated in FIG. 33, on the semiconductor substrate 10 of, e.g., a silicon substrate, the inter-layer insulation film 12 of, e.g., silicon oxide film is formed.

On the semiconductor substrate 10 with the inter-layer insulation film 12 formed on, the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed. The first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed in the same layer. The plural comb teeth 15 a of the first comb-shaped interconnection 14 a and the plural comb-teeth 15 b of the second comb-shaped interconnection 14 b are formed alternately. The first comb-shaped interconnection 14 a is connected to, e.g., a first potential. The second comb-shaped interconnection 14 b is connected to, e.g., a second potential different from the first potential. The first potential is, e.g., a power supply potential. The second potential is, e.g., the ground potential.

On the semiconductor substrate 10 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, the plural first electrodes 16 a and the plural second electrodes 16 b are formed, projected perpendicularly to the surface of the semiconductor substrate 10. The plural first electrodes 16 a and the plural second electrodes 16 b are formed alternately. As viewed from above the semiconductor substrate 10, the plural first electrodes 16 a and the plural second electrodes 16 b are arranged in a matrix as a whole.

As detailed below, the first electrodes 16 a are formed of the conductor plugs 22 a, the conduction layers 24 a, the conductor plugs 30 a, 30 b, the conduction layers 32 a and the conductor plugs 62 a sequentially stacked.

As detailed below, the second electrodes 16 b are formed of the conductor plugs 22 b, the conduction layer 24 b, the conductor plugs 30 c, 30 d, the conduction layers 32 b and the conductor plugs 62 b sequentially stacked.

The plural first electrodes 16 a and the plural second electrodes 16 b are buried respectively in the inter-layer insulation films 18, 26, 34, 42.

On the inter-layer insulation film 12 with the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b formed on, the inter-layer insulation film 18 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 18, the contact holes 20 a arriving at the first comb-shaped interconnection 14 a and the contact holes 20 b arriving at the second comb-shaped interconnection 14 b are formed.

The conductor plugs 22 a, 22 b are respectively buried in the contact holes 20 a, 20 b.

On the inter-layer insulation film 18 with the conductor plugs 22 a, 22 b buried in, the linear conduction layers 24 a, 24 b are formed. The linear conduction layers 24 a are connected to the conductor plugs 22 a, and the linear conduction layers 24 b are connected to the conductor plugs 22 b.

On the inter-layer insulation film 18 with the linear conduction layers 24 a, 24 b formed on, the inter-layer insulation film 26 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 26, the contact holes 28 a, 28 b respectively arriving at the linear conduction layers 24 a and the contact holes 28 c, 28 d respectively arriving at the linear conduction layers 24 b are formed.

The conductor plugs 30 a, 30 b are respectively buried in the contact holes 28 a, 28 b. The conductor plugs 30 a are connected to one ends of the linear conduction layers 24 a, and the conductor plugs 30 b are connected to the other ends of the linear conduction layers 24 a.

The conductor plugs 30 c, 30 d are respectively buried in the contact holes 28 c, 28 d. The conductor plugs 30 c are connected to one ends of the linear conduction layers 24 b, and the conductor plugs 30 d are connected to the other ends of the linear conduction layers 24 b.

On the inter-layer insulation film 26 with the conductor plugs 30 a-30 d buried in, the linear conduction layers 32 a, 32 b are formed.

The linear conduction layers 32 a have one ends connected to one ends of the linear conduction layers 24 a via the conductor plugs 30 a. The linear conduction layers 32 a have the other ends connected to the other ends of the linear conduction layers 24 a via the conductor plugs 30 b.

The linear conduction layers 32 b have one ends connected to one ends of the linear conduction layers 24 b via the conductor plugs 30 c. The linear conduction layers 32 b have the other ends connected to the other ends of the linear conduction layers 24 b via the conductor plugs 30 d.

On the inter-layer insulation film 26 with the linear conduction layers 32 a, 32 b formed on, the inter-layer insulation film 34 of, e.g., silicon oxide film is formed.

In the inter-layer insulation film 34, the contact holes 60 a arriving at one ends of the linear conduction layers 32 a and the contact holes 60 b arriving at one ends of the conduction layers 32 b are formed.

The conductor plugs 62 a, 62 b are respectively buried in the contact holes 60 a, 60 b. The conductor plugs 62 a are connected to one ends of the linear conduction layers 32 a, and the conductor plugs 62 b are connected t one ends of the linear conduction layers 32 b.

On the inter-layer insulation film 34 with the conductor plugs 62 a, 62 b buried in, the third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b are formed (see FIG. 35). The third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b are formed in the same layer. The third comb-shaped interconnection 64 a has a plurality of comb teeth 65 a. The plural comb teeth 65 a of the third comb-shaped interconnection 64 a are formed in parallel with each other. The fourth comb-shaped interconnection 64 b has a plurality of comb teeth 65 b. The plural comb teeth 65 b of the fourth comb-shaped interconnection 64 b are formed in parallel with each other. The plural comb teeth 65 a of the third comb-shaped interconnection 64 a and the plural comb teeth 65 b of the fourth comb-shaped interconnection 64 b are formed alternately. In other words, the plural comb teeth 65 a of the third comb-shaped interconnection 64 a and the plural comb teeth 65 b of the fourth comb-shaped interconnection 64 b are formed in combination with each other. The comb teeth 65 a of the third comb-shaped interconnection 64 a and the comb teeth 65 b of the fourth comb-shaped interconnection 64 b are opposed to each other. One of the comb tooth 65 b of the fourth comb-shaped interconnection 64 b is arranged between one of the comb tooth 65 a of the third comb-shaped interconnection 64 a and the other comb tooth 65 b of the third comb-shaped interconnection 64 b. The other comb tooth 65 a of the third comb-shaped interconnection 64 a is arranged between one of the comb tooth 65 b of the fourth comb-shaped interconnection 64 b and the other comb tooth 65 b of the fourth comb-shaped interconnection 64 b. The third comb-shaped interconnection 64 a is connected to the same potential as the first comb-shaped interconnection 14 a, i.e., the first potential. The fourth comb-shaped interconnection 64 b is connected to the same potential as the second comb-shaped interconnection 14 b, i.e., the second potential.

The comb teeth 65 b of the third comb-shaped interconnection 64 a are connected to one ends of the linear conduction layers 32 a via the conductor plugs 62 a.

The comb teeth 65 b of the fourth comb-shaped interconnection 64 b are connected to one ends of the linear conduction layers 32 b via the conductor plugs 62 b.

On the inter-layer insulation film 34 with the third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b formed on, the inter-layer insulation film 42 of, e.g., silicon oxide film is formed.

Thus, the first electrodes 16 a including the conductor plugs 22 a, the conduction layers 24 a, the conductor plugs 30 a, 30 b, the conduction layer 32 a and the conductor plugs 62 a are constituted.

The second electrodes 16 b including the conductor plugs 22 b, the conduction layers 24 b, the conductor plugs 30 c, 30 d, the conduction layer 32 b and the conductor plugs 62 b are constituted.

As described above, in the semiconductor device according to the present embodiment, the first comb-shaped interconnection 14 a is formed below the first electrodes 16 a, and also above the first electrodes 16 a, the third comb-shaped interconnection 64 a electrically connected to the first electrodes 16 a is formed. In the present embodiment, as described above, the second comb-shaped interconnection 14 b is formed below the second electrodes 16 b, and also above the second electrodes 16 b, the fourth comb-shaped interconnection 64 b electrically connected to the second electrodes 16 b is formed. Thus, according to the present embodiment, the capacitor element can have good frequency characteristics.

(Manufacturing Method of Capacitor Element and Semiconductor Device)

Next, the method of manufacturing the capacitor element according to the present embodiment and the semiconductor device including the capacitor element will be explained with reference to FIG. 36A to FIG. 43. FIGS. 36A to 43 are views of the semiconductor device according to the present embodiment in the steps of the method for manufacturing the semiconductor device. FIGS. 36A, FIG. 37A, FIG. 38A, FIG. 39A, FIG. 40A and FIG. 41A are sectional views along the A-A′ line respectively in FIG. 36B, FIG. 37B, FIG. 38B, FIG. 39B, FIG. 40B and FIG. 41B. FIG. 42 is a sectional view, and FIG. 43 is a plan view. FIG. 42 is the sectional view along the A-A′ line in FIG. 43.

First, the step of forming the inter-layer insulation film 12 on the semiconductor substrate 10 to the step of forming the conduction layers 32 a, 32 b on the inter-layer insulation film 26 are the same as those of the method of manufacturing the semiconductor device according to the first embodiment described above with reference to FIGS. 4A to 8B, and their explanation is not repeated (see FIG. 36A to FIG. 40B).

Then, on the inter-layer insulation film 26 with the conduction layers 32 a, 32 b formed on, the inter-layer insulation film 34 of, e.g., silicon oxide film is formed on the entire surface by, e.g., CVD.

Then, the contact holes 60 a arriving at one ends of the conduction layers 32 a and the contact holes 60 b arriving at the other ends of the conduction layers 32 a are formed in the inter-layer insulation film 34 by photolithography.

Then, a barrier film and a tungsten film are formed on the entire surface by, e.g., CVD.

Next, the tungsten film and the barrier film are polished by, e.g., CMP until the surface of the inter-layer insulation film 34 is exposed by, e.g., CMP. Thus, the conductor plugs 62 a, 62 b of, e.g., tungsten are buried respectively in the contact holes 60 a, 60 b (see FIGS. 41A and 41B).

Then, on the entire surface, a conduction film of aluminum or others of an about 200-300 nm-film thickness is formed by, e.g., sputtering.

Next, the conduction film is patterned by photolithography. Thus, on the inter-layer insulation film 34, the third comb-shaped interconnection 64 a having the plural comb teeth 65 a and the fourth comb-shaped interconnection 64 b having the plural comb teeth 65 b are formed. The comb teeth 65 a of the third comb-shaped interconnection 64 a are electrically connected to one ends of the condition layers 32 a via the conductor plugs 62 a. The comb teeth 65 b of the fourth comb-shaped interconnection 64 b are electrically connected to one ends of the conduction layers 32 b via the conductor plugs 62 b.

The case that the third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b are formed by forming a conduction film of aluminum or others and etching the conduction film is exemplified. However, the method of forming the third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b is not limited to this. For example, it is possible that contact holes for the conductor plugs 62 a, 62 b to be buried in and trenches for the comb-shaped interconnections 64 a, 64 b to be buried in are formed in the inter-layer insulation film, a conduction film of Cu is formed in the contact holes and the trenches and on the inter-layer insulation film, and the conduction film is polished until the surface of the inter-layer insulation film is exposed to thereby bury the conductor plugs 62 a, 62 b of Cu and the comb-shaped interconnections 64 a, 64 b of Cu in the inter-layer insulation film (not illustrated). That is, the conductor plugs 62 a, 62 b and the comb-shaped interconnections 64 a, 64 b may be formed by dual damascene. In this case, the conductor plugs 62 a of Cu and the third comb-shaped interconnection 64 a of Cu are formed integral, and the conductor plugs 62 b of Cu and the fourth comb-shaped interconnection 64 b of Cu are formed integral.

Then, on the entire surface, the inter-layer insulation film 42 of, e.g., silicon oxide film is formed by, e.g., CVD.

Thus, the semiconductor device according to the present embodiment is manufactured (see FIG. 42 and FIG. 43).

(Modification)

The capacitor element according to a modification of the present embodiment and the semiconductor device including the capacitor element will be explained with FIG. 44. FIG. 44 is a sectional view of the semiconductor device according to the present modification.

The capacitor element according to the present modification and the semiconductor device including the capacitor element are characterized mainly in that the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b are respectively connected by the linear conduction layers 30 e, 30 f buried in the inter-layer insulation film 26.

As described above, the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b may be connected respectively by the conduction layers 30 e, 30 f without connecting the linear conduction layers 24 a, 24 b and the linear conduction layers 32 a, 32 b respectively by the conductor plugs 30 a-30 d.

[Modified Embodiments]

The present invention is not limited to the above-described embodiments and can cover other various modifications.

For example, in the above-described embodiments, the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are formed of a metal of aluminum or others. However, the first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b are not limited to metal. The first comb-shaped interconnection 14 a and the second comb-shaped interconnection 14 b may be formed of, e.g., polycrystalline silicon or others.

In the above-described embodiments, the third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b are formed of the metal of aluminum or others. However, the third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b may not be essentially formed of metal. The third comb-shaped interconnection 64 a and the fourth comb-shaped interconnection 64 b may be formed of, e.g., polycrystalline silicon or others.

In the above-described embodiments, the conduction layers 24 a, 24 b, 32 a, 32 b, 40 a, 40 b, 44 a, 44 b, 52 a, 52 b are formed of the metal of aluminum or others. However, the material of the conduction layers 24 a , 24 b, 32 a, 32 b, 40 a, 40 b, 44 a, 44 b, 52 a, 52 b is not limited to metal. The conduction layers 24 a, 24 b, 32 a, 32 b, 40 a, 40 b, 44 a, 44 b, 52 a, 52 b may be formed of, e.g., polycrystalline silicon or others.

In the third embodiment, the electrodes 16 a, 16 b are formed only between the comb-shaped interconnections 14 a, 14 b and the comb-shaped interconnections 64 a, 64 b. However, the electrodes 16 c, 16 d as illustrated in FIG. may be further formed below the comb-shaped interconnections 14 a, 14 b.

In the third embodiment, the electrodes 16 a, 16 b are formed only between the comb-shaped interconnections 14 a, 14 b and the comb-shaped interconnections 64 a, 64 b. However, the same electrodes as the electrodes 16 a, 16 b may be formed above the comb-shaped interconnections 64 a, 64 b.

All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. 

1. A capacitor element comprising: a first comb-shaped interconnection formed over a substrate and including a first comb tooth; a second comb-shaped interconnection formed over the substrate and including a second comb tooth opposed to the first comb tooth; a first electrode and a second electrode opposed to each other with opposed surfaces of the first electrode and the second electrode intersecting a longitudinal direction of the first comb tooth and the second comb tooth; and a first dielectric layer formed between the first electrode and the second electrode, the first electrode being connected to the first comb tooth, and the second electrode being connected to the second comb tooth.
 2. The capacitor element according to claim 1, further comprising a third electrode and a fourth electrode opposed to each other with opposed surfaces of the third electrode and the fourth electrode intersecting the longitudinal direction of the first comb tooth and the second comb tooth, the first comb-shaped interconnection further including a third comb tooth parallel with the first comb tooth, the second comb-shaped interconnection further including a fourth comb tooth parallel with the second comb tooth, and the third electrode being connected to the third comb tooth, and the fourth electrode being connected to the fourth comb tooth.
 3. The capacitor element according to claim 1, further comprising: a fifth electrode formed below the first electrode and including a top connected to the first comb-shaped interconnection; a sixth electrode formed below the second electrode and including a top connected to the second comb-shaped interconnection and opposed to the fifth electrode; and a second dielectric layer formed between the fifth electrode and the sixth electrode.
 4. The capacitor element according to claim 1, further comprising: a third comb-shaped interconnection formed over the substrate and including a fifth comb tooth; and a fourth comb-shaped interconnection formed over the substrate and having a sixth comb tooth opposed to the fifth comb tooth, a top of the first electrode being connected to the fifth comb tooth, and a top of the second electrode being connected to the sixth comb tooth.
 5. The capacitor element according to claim 1, wherein the first electrode or the second electrode is formed of conduction layers and conductor plugs alternately stacked.
 6. The capacitor element according to claim 2, wherein the third electrode or the fourth electrode is formed of conduction layers and conductor plugs alternately stacked.
 7. The capacitor element according to claim 1, wherein the first electrode or the second electrode is formed of a plurality of conduction layers stacked.
 8. The capacitor element according to claim 2, wherein the third electrode and the fourth electrode is formed of a plurality of conduction layers stacked.
 9. The capacitor element according to claim 5, wherein one conduction layer of a plurality of the conduction layers and another conduction layer formed over said one conduction layer are connected via a plurality of the conductor plugs formed directly on said one conduction layer.
 10. The capacitor element according to claim 9, wherein said a plurality of conductor plugs are formed on both ends of said one conduction layer.
 11. The capacitor element according to claim 2, wherein the second comb tooth are arranged between the first comb tooth and the third comb tooth, and the third comb tooth are arranged between the second comb tooth and the fourth comb tooth.
 12. The capacitor element according to claim 1, wherein the first comb-shaped interconnection and the second comb-shaped interconnection are formed of polycrystalline silicon, a metal containing Cu or a metal containing Al.
 13. A semiconductor device comprising a capacitor element formed over a semiconductor substrate, the capacitor element including a first comb-shaped interconnection formed over the substrate and including a first comb tooth; a second comb-shaped interconnection formed over the substrate and including a second comb tooth opposed to the first comb tooth; a first electrode and a second electrode opposed to each other with opposed surfaces of the first electrode and the second electrode intersecting a longitudinal direction of the first comb tooth and the second comb tooth; and a first dielectric layer formed between the first electrode and the second electrode, the first electrode being connected to the first comb tooth, and the second electrode being connected to the second comb tooth.
 14. The semiconductor device according to claim 13, wherein the capacitor element further includes a third electrode formed below the first electrode and including a top connected to the first comb-shaped interconnection; a fourth electrode formed below the second electrode and including a top connected to the second comb-shaped interconnection and opposed to the third electrode; and a second dielectric layer formed between the third electrode and the fourth electrode.
 15. The semiconductor device according to claim 13, wherein the capacitor element further includes a third comb-shaped interconnection formed over the substrate and having a fifth comb tooth; and a fourth comb-shaped interconnection formed over the substrate and including a sixth comb tooth opposed to the fifth comb tooth, a top of the first electrode connected to the fifth comb tooth, and a top of the second electrode being connected to the sixth comb tooth. 